This project is a cooperative effort between the National Ocean Service, National Centers for Coastal Ocean Science, Center for Coastal Monitoring and Assessment, the University of Hawaii, BAE Systems Spectral Solutions and Analytical Laboratories of Hawaii, LLC. The goal of the work was to incorporate previously developed mapping methods to produce coral reef habitat maps for the Main Eight Hawaiian Islands. GPS field observations were used to establish the thematic accuracy of this thematic product. 39 benthic habitat characterizations were completed in UTM Zone 5 for this work.

Planar coordinates are encoded using Coordinate Pair
Abscissae (x-coordinates) are specified to the nearest 0.000032
Ordinates (y-coordinates) are specified to the nearest 0.000032
Planar coordinates are specified in meters

The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257222.

The National Ocean Service is preparing digital map products of these biotic resources and coordinates a long-term monitoring program that can detect and predict change in U.S. coral reefs, and their associated habitats and biological communities. The goal of the work was to implement previously developed coral reef mapping methods to produce GIS map products of benthic habitats by photo interpreting ortho-rectified remotely sensed imagery. These Accuracy Assessment point data were generated to assess the thematic accuracy of these habitat maps.

After photo interpretation was completed, at minimum of 25 random geographically referenced points were acquired in each detailed benthic structure and cover class. This is done using a random point generator program obtained from the ESRI website, which generates random points inside an ArcView GIS polygon class. Waypoint files are generated from these random points and all waypoints, which could be safely accessed, are navigated to using a Trimble GeoExplorer 3 GPS data logger and a benthic habitat characterization was conducted. Eight test areas have been defined and the final data set meets the goal of 25 points per detailed structure and cover habitat.

The geographic coordinate positions of the points in this thematic data were acquired by GPS using a Trimble GeoExplorer 3 with a customized data dictionary designed to reflect the NOAA Coral Classification Scheme for Benthic Habitats of the Pacific. All habitat determinations were made in the field, recorded in the GPS data logger and seamlessly transferred to ArcView GIS using Trimble Path Finder Office Software.

Point positional accuracy is determined by two tests producing circular RMS statistics. First, point GPS data were acquired by repeated occupation of a registered survey monument that has been recently recovered and positioned using survey grade GPS buy the National Geodetic Survey. Second, replicate GPS positions were collected after navigating to a way point by boat to estimate the positional error generated from variables due to environmental conditions offshore. The 95% sigma RMS accuracy error was calculated to be 1.08 meters and the precision calculated to be 0.96 meters on 141 measurements on registered monuments. The navigation accuracy error was calculated to be 1.36 meters with precision calculated to be 1.11 meters. Each GPS measurement was the average of 100 GPS positions. Thus, all point features in these accuracy assessment data meet the NOAA contract standard of 95% sigma of 5 meters.

Data are complete for this imagery bundle. Habitat attributes are determined by direct observation in the field. These data are considered truth at the time of collection. Habitat types are subject to change over time due to population dynamics of the dominant biological communities.

These data were objectively managed. They were with held from the photo interpreter during map making. The Coral Reef Assessment and Monitoring Program (CRAMP) of the Hawaii Institute of Marine Biology (HIMB) maintained these data at facilities other than ALH. Ultimately, these data were used to prepare the error matrix upon when the statistical report of the thematic accuracy of the maps was generated.

Transfer of the habitat assessment data is seamless from the field determination to the final GIS product. The data is not transcribed or rewritten by hand. Errors in processing are not expected.

The National Oceanic and Atmospheric Administration (NOAA) National Centers for Coastal Ocean Science (NCCOS) will publish this data on CD-ROM. NCCOS Biogeography Branch does not guarantee the accuracy of the geographic features or attributes. Please see the metadata records for each data set for complete information on the source, limitations, and proper use.